Build Flutter App — Without Re-launching Your Site
React Native & Flutter shipped to both stores
What you're seeing
You want a single Flutter codebase that feels native on both iOS and Android with a custom design system.
Our approach
We build the app in Flutter with proper state management (Riverpod or Bloc), a custom design system, and a release pipeline to both stores from day one.
Symptoms teams come to us with
- Frames drop on scroll and animations feel janky
- Builds fail with cryptic Xcode or Gradle errors on CI
- Crash-free rate is slipping on the Play or App Store
- An upgrade or store submission keeps getting blocked
What we check first
- 01JS-thread saturation, bridge calls and un-recycled lists
- 02Native dependency, Podfile and Gradle version mismatches
- 03Real-device crash classes hidden from the simulator
- 04Signing, provisioning and store-review blockers
What you get
Concrete deliverables, no fluff
Every engagement ends with measurable, documented outcomes — no black-box agency reports.
Reproduction of the bug or perf issue on a real device
Implementation behind a PR you review
Verified fix on iOS and Android (real hardware, not just simulator)
Release notes + App Store / Play Store update checklist
From brief to shipped fix
A transparent, low-risk process — a senior engineer reads your brief personally, and nothing starts until you approve a written plan and price.
Diagnose
A senior engineer reviews your brief, reproduces the issue, and pinpoints the real root cause — not the symptom — before any code is touched.
Scoped plan & quote
You get a written plan to build Flutter App, a firm timeline, and a fixed quote. Nothing starts until you approve it — no surprise invoices.
Ship the fix
We implement on a branch and open a pull request you review, working to your code-review standards on your repo — never a black box.
Verify & hand off
We verify on staging and production, share before/after evidence where it applies, and leave you a short hand-off note so the fix sticks.
Why teams hand this task to Krapton
Senior engineers only
Your brief is read and handled by a senior engineer — no junior hand-off, no sales-rep filter in between.
Root cause, not a patch
We reproduce and fix the underlying cause, then add a guard so the same class of issue does not quietly return.
Your repo, your standards
Every change lands as a pull request you review, on your repository, following your existing review process.
NDA on day one
Confidentiality and IP are covered before we look at a single line of code. All work stays in your accounts.
Fixed quote up front
You approve a written plan and price before work starts. If scope changes, we re-quote in writing — no surprise invoices.
Proof, where it applies
Performance, SEO and reliability work ships with before/after evidence so the result is measurable, not anecdotal.
Three ways to engage
No retainer required. Pick the model that matches the work — pricing for this task starts from $2,500, with a fixed quote before anything starts.
Per task
Most popularOne clearly-scoped fix at a fixed price. Best when you know exactly what is broken and want it handled end to end.
- Fixed quote up front
- One PR, reviewed by you
- No retainer required
Hourly
Pay only for the hours worked. Best for diagnostics, audits, or exploratory work where the scope is still emerging.
- Weekly timesheets
- Pay for what you use
- No minimum commitment
Per sprint
A focused 1–2 week sprint when the work is bigger than one fix but smaller than a full project.
- 1–2 week blocks
- Clear sprint goal
- Scale up or stop anytime
Tooling we use
Industry-standard stack, no proprietary lock-in
Build Flutter App — your questions, answered
How much does it cost to build Flutter App?
Pricing starts from $2,500 and depends on the scope we find during the diagnostic. You get a fixed, written quote before any work begins — most engagements like this run 2–8 weeks.
How long does it take to build Flutter App?
Typically 2–8 weeks for a focused engagement. After a short diagnostic we commit to a firm timeline so you know exactly what to expect.
Will you work directly on our existing codebase?
Yes. We work on your GitHub, GitLab or Bitbucket, ship every change as a pull request you review, and follow your code-review standards — not ours.
What exactly will I have at the end?
Concrete, documented outcomes — Reproduction of the bug or perf issue on a real device, Implementation behind a PR you review, Verified fix on iOS and Android (real hardware, not just simulator), and more. No black-box agency report.
How quickly can you start, and do you sign an NDA?
For a focused task like this we can usually start within 24–48 hours of the brief. We sign an NDA on day one, before we look at any code — yours or ours.
Do you test on real devices, not just the simulator?
Always. Mobile bugs and jank usually only show up on real hardware, especially mid-range Android, so we reproduce and verify on physical devices before we call anything fixed.
Keep exploring
Related tasks and resources to plan your next step with Krapton.
Let's get this off your plate
Send a 60-second brief on Build Flutter App and a senior engineer replies within 24 hours with a plan and a fixed quote. NDA on day one, no retainer required.